Cleavage and Fracture of Minerals

 Cleavage and Fracture of Minerals - Some minerals when struck a sharp blow, break only along certain lines while other minerals break just as easily in one direction as in another. When a mineral has a tendency to break along certain planes, it is said to have cleavage, which is the result of the arrangement of the molecules and atoms. Minerals may have only one plane of weakness or cleavage, or they may have two, three, or more. The second type of breaking, that which is not determined by any arrangement of molecules is called fracture and this also varies among different minerals. Various types of fractures are described as smooth, uneven, ragged, and shell-like.